The prospects for additive manufacturing of bulk TiAl alloy

This paper deals with the prospects for additive manufacturing (AM) of bulk TiAl alloys. A number of AM processes have already been explored in the literature for these intermetallic alloys. The main trend developed in published works concerns a strong crack sensitivity of this relatively brittle material due to rapid successive heating and cooling cycles. Optimised processing conditions have already been achieved for producing sound and crack-free TiAl materials by means of EBM and laser metal deposition processes. This experimental work was particularly focused on the third process, i.e. selective laser melting, to produce fully dense TiAl parts. A series of beads, surface layers and cubes have been manufactured to investigate the microstructural evolution. Post-heat treatments allowed a uniform microstructure to be restored for the intermetallic TiAl alloy.